search for: backend_get_size

...size; uint16_t eflags; bool readonly; bool can_flush; diff --git a/server/backend.c b/server/backend.c index b2054aa2..374d8540 100644 --- a/server/backend.c +++ b/server/backend.c @@ -132,10 +132,13 @@ backend_set_handle (struct backend *b, struct connection *conn, void *handle) int64_t backend_get_size (struct backend *b, struct connection *conn) { + struct b_conn_handle *h = &conn->handles[b->i]; + debug ("%s: get_size", b->name); - /* TODO caching */ - return b->get_size (b, conn); + if (h->exportsize == -1) + h->exportsize = b->get_size (b, conn);...

.../* Wrappers for all callbacks in a filter's struct nbdkit_next_ops. */ +int +backend_reopen (struct backend *b, struct connection *conn, int readonly) +{ + debug ("%s: reopen", b->name); + + backend_close (b, conn); + return backend_open (b, conn, readonly); +} + int64_t backend_get_size (struct backend *b, struct connection *conn) { diff --git a/server/filters.c b/server/filters.c index 1091c2d..78e32bc 100644 --- a/server/filters.c +++ b/server/filters.c @@ -237,6 +237,13 @@ filter_close (struct backend *b, struct connection *conn) * single ‘void *nxdata’ struct pointer (‘b_co...

..._reopen (struct backend *b, struct connection *conn, int readonly) +{ + struct b_conn_handle *h = &conn->handles[b->i]; + + debug ("%s: reopen", b->name); + + if (h->handle != NULL) + backend_close (b, conn); + return backend_open (b, conn, readonly); +} + int64_t backend_get_size (struct backend *b, struct connection *conn) { diff --git a/server/filters.c b/server/filters.c index 1091c2d..78e32bc 100644 --- a/server/filters.c +++ b/server/filters.c @@ -237,6 +237,13 @@ filter_close (struct backend *b, struct connection *conn) * single ‘void *nxdata’ struct pointer (‘b_co...

..._FLAG_HAS_FLAGS; int fl; - if (backend_open (backend, read_only) == -1) + if (backend_open (top, read_only) == -1) return -1; /* Prepare (for filters), called just after open. */ - if (backend_prepare (backend) == -1) + if (backend_prepare (top) == -1) return -1; - size = backend_get_size (backend); + size = backend_get_size (top); if (size == -1) return -1; if (size < 0) { @@ -98,57 +98,57 @@ protocol_common_open (uint64_t *exportsize, uint16_t *flags) /* Check all flags even if they won't be advertised, to prime the * cache and make later request validati...

On 2/12/20 7:40 AM, Richard W.M. Jones wrote: > This was previously used as ‘nxdata’ and stored a tuple of ’b->next’ > and the real filter handle. However after recent changes we don't > need it. We can use ‘b->next’ as nxdata, and the handle is passed to > us by the calling functions. > > Inspired by Eric Blakes observations in this email: Blake's >

...int next_reopen (void *nxdata, int readonly) { - struct b_h *b_h = nxdata; - return backend_reopen (b_h->b, readonly); + struct backend *b_next = nxdata; + return backend_reopen (b_next, readonly); } static int64_t next_get_size (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_get_size (b_h->b); + struct backend *b_next = nxdata; + return backend_get_size (b_next); } static int next_can_write (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_write (b_h->b); + struct backend *b_next = nxdata; + return backend_can_write (b_next); } static int...

...uint64_t offset, uint32_t count) - __attribute__((__nonnull__ (1, 2))); + __attribute__((__nonnull__ (1))); -extern int backend_reopen (struct backend *b, struct connection *conn, - int readonly) - __attribute__((__nonnull__ (1, 2))); -extern int64_t backend_get_size (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_write (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_flush (struct backend *b, struct connection *conn) - __attribute__((__nonn...

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00081.html v2 replaces struct connection *conn = GET_CONN; with GET_CONN; which sets conn implicitly and asserts that it is non-NULL. If we actually want to test if conn is non-NULL or behave differently, then you must use threadlocal_get_conn() instead, and some existing uses do that. Rich.

The third patch is a large but mechanical change which gets rid of passing around struct connection * entirely within the server, preferring instead to reference the connection through thread-local storage. I hope this is a gateway to simplifying other parts of the code. Rich.

...it would require > recompilation, we already state that filter recompilation is par for > the course (since only plugins promise API compatibility). Yes my original version had stuff like: static struct nbdkit_next_ops next_ops = { .reopen = (void *) backend_reopen, .get_size = (void *) backend_get_size, but that wasn't very safe, and exporting struct backend, even opaquely, to the public header didn't sound like a good idea either. (Are C structs always treated the same by name? That could cause a problem for a filter which used "struct backend" for some internal reason I thin...

It's easy to use the sh script to demonstrate that nbdkit is inefficiently calling into .get_size, .can_fua, and friends more than necessary. We've also commented on the list in the past that it would be nice to ensure that when filters call into next_ops, they are not violating constraints (as we've have to fix several bugs in the past where we did not have such checking to protect

...a is a pointer to the next backend in the linked list. - */ - -static int -next_reopen (void *nxdata, int readonly) -{ - struct backend *b_next = nxdata; - return backend_reopen (b_next, readonly); -} - -static int64_t -next_get_size (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_get_size (b_next); -} - -static int -next_can_write (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_write (b_next); -} - -static int -next_can_flush (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_flush (b_next); -} - -static int -next_is_rotational (v...

This is a subset of the last half of the larger 9-patch series. The uncontroversial first half of that series is pushed, but here, I tried to reduce the size of the patches by splitting out some of the more complex changes, so that the rest of the changes remaining in the series are more mechanical. In turn, it forced me to write timing tests, which let me spot another spot where we are wasting

...nore over-length strings. XXX Also ignore non-UTF8? */ + if (s && strnlen (s, NBD_MAX_STRING + 1) > NBD_MAX_STRING) { + controlpath_debug ("%s: export_description: ignoring invalid string", + b->name); + s = NULL; + } + return s; +} + int64_t backend_get_size (struct backend *b) { diff --git a/server/filters.c b/server/filters.c index dd4417be..54abf9a4 100644 --- a/server/filters.c +++ b/server/filters.c @@ -291,6 +291,7 @@ filter_close (struct backend *b, void *handle) static struct nbdkit_next_ops next_ops = { .reopen = backend_reopen, + .expo...

...struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); assert (h->exportsize <= INT64_MAX); /* Guaranteed by negotiation phase */ return count > 0 && offset <= h->exportsize && @@ -291,7 +291,7 @@ int64_t backend_get_size (struct backend *b) { GET_CONN; - struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); controlpath_debug ("%s: get_size", b->name); @@ -305,7 +305,7 @@ int backend_can_write (struct backend *b) { GET_CONN; - struc...

...c b/server/protocol.c index 03862f5f..db40cca3 100644 --- a/server/protocol.c +++ b/server/protocol.c @@ -47,50 +47,43 @@ #include "minmax.h" #include "protocol.h" -static bool -valid_range (struct connection *conn, uint64_t offset, uint32_t count) -{ - uint64_t exportsize = backend_get_size (backend, conn); - - assert (exportsize <= INT64_MAX); /* Guaranteed by negotiation phase */ - return count > 0 && offset <= exportsize && offset + count <= exportsize; -} - static bool validate_request (struct connection *conn, uint16_t cmd, uint1...

This is a retry filter implementation as outlined here: https://www.redhat.com/archives/libguestfs/2019-September/msg00167.html It is only lightly tested. One way to test it is to try an SSH copy (see the commit message for patch 2/2), and in the middle of the copy kill the per-connection sshd on the remote machine. You will see that the copy recovers after a few seconds. Add the nbdkit -v

v1 was here: https://www.redhat.com/archives/libguestfs/2019-September/msg00199.html v2: - Adds a fairly simple yet comprehensive test using sh plugin. - Rebase and retest. Patch 1 is a misc patch not really related to the series. Rich.

..._conn *nxdata = handle; + assert (nxdata->b == b->next && nxdata->conn == conn); if (f->filter.get_size) - return f->filter.get_size (&next_ops, &nxdata, handle); + return f->filter.get_size (&next_ops, nxdata, nxdata->handle); else return backend_get_size (b->next, conn); } @@ -458,10 +481,11 @@ static int filter_can_write (struct backend *b, struct connection *conn, void *handle) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - struct b_conn nxdata = { .b = b->next, .conn = conn }; + struct b_conn *nxda...

v2 was here: https://www.redhat.com/archives/libguestfs/2019-September/msg00221.html I think this is more like "the one". It handles reopen failing correctly, and there is a second test for that. I also ran my sshd tests locally and it worked in all scenarios I could think up (except of course sshd not being available at the start, but we want that to fail). Rich.